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In this Letter we establish clear evidence for the resonant absorption damping mechanism by analyzing observational data from the novel Coronal Multi-Channel Polarimeter (CoMP). This instrument has established that in the solar corona there…

Solar and Stellar Astrophysics · Physics 2015-05-19 G. Verth , M. Goossens , J. Terradas

The origin and evolution of the 1/f power law observed in the energy spectrum of solar coronal and solar wind fluctuations at scales of around an hour is not entirely understood. Several existing theories aim at explaining it, involving…

Solar and Stellar Astrophysics · Physics 2022-10-26 Norbert Magyar , Tom Van Doorsselaere

We present the first Hinode/EIS observations of 5 min quasi-periodic oscillations detected in a transition-region line (He II) and five coronal lines (Fe X, Fe XII, Fe XIII, Fe XIV, and Fe XV) at the footpoint of a coronal loop. The…

Solar and Stellar Astrophysics · Physics 2010-11-11 T. J. Wang , L. Ofman , J. M. Davila

Observations reveal an increase with height of the line width of several coronal spectral lines probably caused by outwardly propagating Alfv{\'e}n waves. However, the spectral line width sometimes shows a sudden decrease at a height…

Astrophysics · Physics 2008-11-26 T. V. Zaqarashvili , R. Oliver , J. L. Ballester

Using the Hinode/EIS 2$"$ spectroscopic observations, we study the intensity, velocity, and FWHM variations of the strongest Fe XII 195.12 \AA\ line along the jet to find the signature of Alfv\'en waves. We simulate numerically the…

Solar and Stellar Astrophysics · Physics 2015-09-23 P. Jelínek , A. K. Srivastava , K. Murawski , P. Kayshap , B. N. Dwivedi

We study the impulsively generated non-linear Alfv\'en waves in the solar atmosphere, and describe their most likely role in the observed non-thermal broadening of some spectral lines in solar coronal holes. We solve numerically the…

Solar and Stellar Astrophysics · Physics 2015-06-05 P. Chmielewski , A. K. Srivastava , K. Murawski , Z. E. Musielak

A simple model of a periodic ensemble of closely packed flux tubes sitting atop a vertically stratified layer reveals that an incident fast wave from below preferentially converts almost immediately to Alfv\'en waves in the flux tubes, with…

Solar and Stellar Astrophysics · Physics 2017-01-18 Paul S. Cally

High-frequency wave phenomena present a great deal of interest as one of the possible candidates to contribute to the energy input required to heat the corona as a part of the AC heating theory. However, the resolution of imaging…

Solar and Stellar Astrophysics · Physics 2023-04-05 Elena Petrova , Norbert Magyar , Tom Van Doorsselaere , David Berghmans

Using data obtained by the EUV Imaging Spectrometer (EIS) onboard Hinode, we have per- formed a survey of obvious and persistent (without significant damping) Doppler shift oscillations in the corona. We have found mainly two types of…

Solar and Stellar Astrophysics · Physics 2012-10-31 Hui Tian , Scott W. McIntosh , Tongjiang Wang , Leon Ofman , Bart De Pontieu , Davina E. Innes , Hardi Peter

Using Parker Solar Probe data from orbits 8 through 17, we examine fluctuation amplitudes throughout the critical region where the solar wind flow speed approaches and then exceeds the Alfv\'en wave speed, taking account of various…

The forbidden lines of [Fe XIII] at 10,747 Angstrom and 10,798 Angsrtom are among the most prominent lines in the near-infrared spectrum of the solar corona. They have been used routinely, both outside and during eclipses, as sensitive…

Solar and Stellar Astrophysics · Physics 2026-01-21 D. P. K. Banerjee , C. E. Woodward , A. Evans , T. R. Geballe , V. Joshi , S. Starrfield

Low-amplitude Doppler-shift oscillations have been observed in coronal emission lines in a number of active regions with the EUV Imaging Spectrometer (EIS) on the Hinode satellite. Both standing and propagating waves have been detected and…

Solar and Stellar Astrophysics · Physics 2015-05-18 John T. Mariska , K. Muglach

We report on multi-wavelength observations spanning radio to X-ray wavelengths of the M dwarf flare star, EV Lacertae, probing the characteristics of the outer atmospheric plasma from the upper chromosphere to the corona. We detect the star…

Astrophysics · Physics 2011-02-11 R. A. Osten , S. L. Hawley , J. Allred , C. M. Johns-Krull , A. Brown , G. M. Harper

We present a novel method to evaluate the Alfven speed and the magnetic field strength along the streamer plasma sheet in the outer corona. The method is based on recent observations of streamer waves, which are regarded as the fast kink…

Solar and Stellar Astrophysics · Physics 2015-05-20 Y. Chen , S. W. Feng , B. Li , H. Q. Song , L. D. Xia , X. L. Kong , Xing Li

The nonthermal broadening of spectral lines formed in the solar corona is often used to seek the evidence of Alfv\'en waves propagating in the corona. To have a better understanding of the variation of line widths at different altitudes, we…

Solar and Stellar Astrophysics · Physics 2021-06-02 Yingjie Zhu , Judit Szente , Enrico Landi

Alfv\'enic waves are thought to play an important role in coronal heating and acceleration of solar wind. Here we investigated the statistical properties of Alfv\'enic waves along spicules (jets that protrude into the corona) in a polar…

Solar and Stellar Astrophysics · Physics 2015-05-28 Takenori J. Okamoto , Bart De Pontieu

The solar ultraviolet intensities of spectral lines originating from Li- and Na-like ions have been observed to surpass the expectations derived from plasmas with coronal approximation. The violation of the coronal approximation can be…

Solar and Stellar Astrophysics · Physics 2024-02-13 Takuma Matsumoto

Torsional Alfv\'en waves are promising candidates for transport of energy across different layers of the solar atmosphere and have been theoretically predicted for decades. Previous detections of Alfv\'en waves so far have however mostly…

Solar and Stellar Astrophysics · Physics 2020-01-15 P. Kohutova , E. Verwichte , C. Froment

We make use of the Parker Solar Probe (PSP) data to explore the nature of solar wind turbulence focusing on the Alfv\'enic character and power spectra of the fluctuations and their dependence on distance and context (i.e. large scale solar…

A comparison between a Coronal Hole (CH) and the adjacent Quiet-Sun (QS) has been performed using spectroscopic diagnostics of Hinode/ the EUV Imaging Spectrometer (EIS). Coronal funnels play an important role in the formation and…

Solar and Stellar Astrophysics · Physics 2015-11-04 P. Kayshap , D. Banerjee , A. K. Srivastava